Which brings the interesting question : what is the real reason behind it ?
It's pretty much everything - better aircraft, better engines, better avionics, better protection against 'dumbass' (e.g. CFIT), better air traffic control and TCAS, better training, better CRM, better oversight. It's literally the incorporation of lessons learned from decades of air disasters.
And yes, there are still areas of concern - fatigue being a big one, another being erosion of pilot skill among the newbies with blind obedience to SOP (e.g. "children of the magenta line").
I also don't see much being done to effectively address 'pilot suicide', which has sadly and disturbing been moving up the list of accident causes.